NEWBURYPORT — Charlie Crocker has been fishing the local waters for more than 30 years, but he’s never pulled up a fish like the one he caught earlier this summer.
Small, sleek, striped like a tiger — it looked somewhat like the mackerel that are common in local waters. But it was just different enough that Crocker knew it was a fish that normally shouldn’t be here. He was right. It was a bonito — a gamefish that typically ventures no farther north than the southern coast of Cape Cod. He caught it off Hampton Shoal Ledge on the New Hampshire seacoast, more than 100 miles north of its usual habitat in Nantucket Sound.
“I’ve been fishing here for 30 years and I’ve never seen one,” said Crocker, who operates a fishing charter boat Mistie C out of Newburyport.
He’s not alone. Last week a Plum Island fisherman posted online a photo of a fish he couldn’t identify — which fellow fishermen recognized as a bonito. He caught it off the Isles of Shoals, a cluster of islands six miles east of Portsmouth, N.H., not far from where Crocker caught his fish.
Turns out, this is a year for surprises in the waters off Newburyport and all along the New England coast.
“All bets are off this year,” said Mike Armstrong of the state Division of Marine Fisheries.
Armstrong, who studies fish populations and migration patterns, wasn’t surprised to hear that a bonito had been caught in local waters. It fits the pattern of what he’s been seeing.
At least three other species of fish not typically found this far north — black sea bass, scup and fluke — have also been found in north coastal Massachusetts waters, he said. Like the bonito, those fish are usually found in the warmer waters off Cape Cod and farther south.
“We’re now starting to see them with regular frequency,” Armstrong said, noting that he was with a fishing party this summer that caught a bonito off Stellwagen Bank, an extensive fishing ground located between Cape Ann and the northern tip of Cape Cod.
The reason is ocean temperatures. This year’s temperatures were abnormally high, a few degrees above normal, but just enough to break records.
“For cold-blooded animals (like fish), that makes a huge difference,” Armstrong said. It extends the zone of migration northward up the coast. Studies in recent years have shown that migration patterns for fish found off the New England coast have been gradually moving northward, as ocean temperatures slowly but steadily warm.
That pattern also drives familiar species that have traditionally been found in local waters to migrate.
“For northern shrimp and cod, it could have really bad effects,” Armstrong said, noting that the local shrimp fishery could be especially hard hit. Northern shrimp, a small species that typically measures about 2 inches or so long, are fished in the mid-winter months.
“We may be saying goodbye to that fishery,” he said.